1. Field of the Invention
An aspect of the present invention relates to an error correction code (ECC) format, and more particularly, to an error correction block having an extended format compatible with a standardized format of a conventional error correction block, a method and apparatus for generating the error correction block, and a method of correcting an error using the error correction block.
2. Description of the Related Art
In existing optical disc systems such as digital versatile discs (DVDs), high definition DVDs (HD DVDs), and Blu-ray discs, performance of correction of a burst error due to a scratch or a fingerprint and correction of a random error due to dust is determined according to a standard error correction block format. When a disc is used, reliability of data recorded onto the disc is gradually decreased due to dust, scratches, or fingerprints when recording or reproducing the disc. In particular, a burst error (such as a scratch due to a physical cut on a surface of a disc) is fatal to the reliability of data. Therefore, it is difficult to recover data whose reliability is deteriorated due to a burst error.
According to conventional standards, continuous errors having a length corresponding to about 16 rows (16*182+10 bytes), 32 rows (32*182+10 bytes), and 64 rows (64*182+10 bytes) in an ECC format can be corrected with respect to a DVD, an HD DVD, and a Blu-ray disc, respectively. Although a physical length corresponding to such correctable continuous error length may be different according to recording density, continuous errors corresponding to physical lengths of about 6 mm, 6.4 mm, and 9 mm can be corrected with respect to a DVD, an HD DVD, and a Blu-ray disc, respectively.
As described above, a disc becomes corrupted due to deterioration caused by the repetitive use of the disc and data reliability is decreased due to continuous errors such as scratches or fingerprints. A physical cut such as a scratch on a surface of a disc may occur when an objective lens of a pickup used for recording/reproducing data collides with the surface of the disc or due to user's carelessness. As a result, the life of the disc is shortened. In particular, even though data is reliable when recorded, if a physical cut such as a scratch occurs on a surface of the disc onto which the data has been recorded, it is highly likely that the data will fail in terms of error correction when the data is reproduced.
When an error cannot be corrected during reproduction because of the deterioration of data reliability, information recorded by a user will be lost. Accordingly, an ECC format with improved error correction performance is desired. Furthermore, when a new ECC format is used to increase the data reliability without considering compatibility with an existing ECC format, reproduction compatibility with existing products is not guaranteed, which may greatly restrict the use of discs.